化学学报 ›› 2009, Vol. 67 ›› Issue (24): 2779-2784. 上一篇    下一篇

研究论文

基于过渡金属离子与三联吡啶的配位作用构筑全共轭层-层
自组装超薄功能膜

潘月秀1,佟斌1,支俊格1,赵玮1,申进波1,石建兵1,董宇平2   

  1. 1. 北京理工大学
    2. 北京理工大学材料科学与工程学院
  • 投稿日期:2009-04-30 修回日期:2009-06-15 发布日期:2010-02-04
  • 通讯作者: 董宇平 E-mail:chdongyp@bit.edu.cn

Full-conjugated Layer-by-Layer self-assembly Ultrathin Functional Films Fabricted from Terpyridine and Transition Metal Ions based on Coordinate Interaction

Pan Yue-Xiu1, 1, 1, 1, 1, 1,   

  • Received:2009-04-30 Revised:2009-06-15 Published:2010-02-04

本文利用所合成的4'-(4'''-重氮基)苯基-(2,2':6',2'')-三联吡啶氟硼酸盐(Diazo-tpy)在紫外光照射下的光分解反应特性,实现三联吡啶基团与基片之间形成共轭价键连接,这不仅提高了自组装膜的稳定性,而且降低了载流子在两者之间传输时的阻抗;在此基础上,通过两端含三联吡啶的直线型配体1,4-二-(2,2':6',2''-三联吡啶)基苯(Bi-tpy)与四种过渡金属离子(Mtn+:Pt4+、Ru3+、Rh3+、Pd2+)之间的配位作用,通过层-层自组装制备了全共轭金属-有机自组装超薄功能膜。由紫外-可见光谱跟踪自组装过程证明了自组装过程的成功实现,还分析了金属离子的种类对自组装的影响规律。光电转换测试表明Bi-tpy/Ru3+自组装膜要比Bi-tpy/ Pt4+具有更明显的光电转换性能;同时,由于缺陷与阻抗随层数的增加而增大的原因,在自组装6层时光电流达到最大值。这为我们设计新型光电转换器件提供参考依据。

关键词: 三联吡啶, 过渡金属离子, 层-层自组装, 配位相互作用, 光电性能

A novel conjugated light-sensitive diazonium-containing compound, 4'-(2,2':6',2''-terpyridyl) benzenediazonium tetrafluoroborate (Diazo-tpy) was firstly synthesized and used to modify substrate by electrostatic interaction. Following the decomposition of diazonium group of Diazo-tpy under UV irradia-tion, the ionic bonds between the diazonium salt and substrate are converted to the covalent bonds. The ter-pyridine-containing monolayer film anchoring on the substrate is very stable. Specially, the π-conjugated system of the terpyridinyl groups is linked to the surface of the substrate, which can greatly facilitate the transport of charges between them. Furthermore, the layer-by-layer (LBL) self-assembled (SA) films of 4'?4'''-(1,4-phenyl)-bis(2,2':6',2''-terpyridine) (Bi-tpy) and different transition metal ions (Pt4+、Ru3+、Rh3+、Pd2+) were fabricated on the tpy-modified substrate, and were well characterized using UV-vis absorption spectroscopy. The UV-vis analytic results indicate that the LBL Bi-tpy/Mtn+ SA multilayer films, having axial ligand between metal atom and terpyridyl group, have been successfully fabricated and a pro-gressive assembly runs regularly with almost equal amount of deposition in each cycle. Under illumination, the SA films on ITO shows an effective photoinduced charge transfer and changed the current density of the ITO. The result revealed that the photoelectric conversion property of Bi-tpy/Ru film is higher than that of Bi-tpy/Pt film. With an increase in the layer number, the photocurrent rises and reaches its maximum at 6 bilayers. Further increment leads to a current drop due to the increase in probability of objection and the cell resistance. The results allow us to design new materials for more optoelectronic applications.

Key words: terpyridine, transition metal ion, layer-by-layer self-assembly, coordinate interaction, photoelectric property